1. Field of the Invention
The present invention relates to a cleaning method and a cleaning cassette suitable for use in cleaning a developing electrode of an electrophotographic apparatus.
2. Description of the Prior Art
An electrophotographic apparatus has been known in which images are recorded in selected frames on an electrophotographic film and the images thus recorded are projected and/or copied as desired. Also known is a cassette having a case accommodating a roll of an electrophotographic film in the form of a tape. One example of the aforesaid cassette is disclosed in U.S. Pat. Nos. 4,572,649 and 4,685,638. This type of film is suitable for use in recording and retrieving a large amount of documents, and offers various advantages which could never be attained by conventional films made of a silver halide material. The recording of images on this type of film is effected through a series of operations including charging/exposure and development performed by a process head a typical example of which is disclosed in U.S. Pat. Nos. 4,591,543, 4,600,291, 4,622,915, 4,623,240, 4,624,554 and so on.
More specifically, the process head is equipped with a charring/exposure section, a developing section, a drying section and a fixing section, and the electrophotographic film is made to pass through these sections successively. In the developing section, the image is developed by application of a sufficient amount of developer over the entire area of the exposed region under application of a bias voltage to a developing electrode provided in the developing section, whereby a clear visible image is obtained.
A problem is encountered in this connection in that solid contents of the developer are accumulated partly because of an electrostatic force which acts to attract the solid contents onto the developing electrode and partly because of the drying of the developer remaining on the electrode. The accumulation of the solid contents on the electrode, when it has become heavy, seriously deteriorates the bias effect of the developing electrode and impairs the passage of the developer. In order to obviate this problem, it is necessary to periodically clean the developing electrode so as to get rid of solid matter attaching thereto. Such a cleaning work, however, is not easy because the developing electrode is recessed from the surface of the process head.